JPH10101391A - Admixture for concrete and concrete material added with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an admixture relieving or unnecessitating compaction at the time of concrete placing when added to fresh concrete by incorporating an acrylamide polymer contg. units derived from three kinds of specified compds. SOLUTION: This high flowability admixture is made of a polymer contg. 10-98wt.% units derived from a compd. represented by formula I (where R<1> is H or CH3 ), 1-60wt.% units derived from a compd. represented by formula II (where R<2> is H or CH3 , R<3> is 1-4C alkylene, X<1> is CONH or COO and X<2> is H, an alkali metal, an ammonium salt or an org. ammonium salt) and 1-40% units derived. from a compd. represented by formula III (where R<4> is H or CH3 , X<3> is CN, COOR<7> , COR<8> , etc., and R<7> is H, an alkali metal, an ammonium salt, 1-4C alkyl, etc.). When this admixture is added to fresh concrete, high flowability, high fillability and high separation resistance are imparted and compaction at the time of concrete placing is relieved or unnecessitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an admixture for high-fluidity concrete and a concrete material to which the admixture is added. More specifically, civil engineering, construction, concrete products, etc., which provide fresh concrete with high fluidity, high filling properties, and high separation resistance, reduce or eliminate compaction during casting, and improve the environment against noise. The present invention relates to a high-fluidity concrete admixture added to a concrete structure.

[0002]

2. Description of the Related Art In recent years, demands for high-fluidity concrete have been increasing due to simplification of on-site work or the complexity and diversification of structures due to earthquakes and environmental beautification. Generally, in order to increase the fluidity of fresh concrete, water or a water reducing agent is added. However, only by this, material separation occurs, coarse aggregates are entangled, the filling property is reduced, and uniform concrete cannot be obtained. Therefore, the strength is reduced. Therefore, the addition of a water-soluble polymer and the blending of fine powder have been studied for the purpose of suppressing the material separation.

[0003] Commonly used water-soluble polymers include cellulose derivatives such as methylcellulose ether, hydroxypropylmethylcellulose ether, methylhydroxyethylmethylcellulose ether, hydroxyethylcellulose ether and hydroxypropylcellulose ether, polysaccharides, curdlan, and dextran. , Starch, xanthan gum and the like. On the other hand, when these water-soluble polymers are added in an amount sufficient to suppress material separation, there is a problem that the viscosity of fresh concrete increases and the fluidity decreases. (JP-A-5-139806).

[0004] When a water reducing agent used to enhance the flowability of fresh concrete is used in combination, the flowability is often impaired due to the interaction with the water reducing agent. Due to such obstruction, it is extremely difficult to secure the desired viscosity and fluidity. (Japanese Patent Laid-Open No. 6
-293542, JP-A-8-12397). In addition, saccharides such as cellulose derivatives have many problems such that they cannot be stored for a long time because they rot in an aqueous solution.

Japanese Patent Publication No. 1-59989 discloses 2-acrylamido-2-methylpropanoic acid-N, N'-dimethylacrylamide copolymer, which is used for underwater concrete. The invention exerts an aggregating action on cement over time, leading to a decrease in fluidity of fresh concrete over time. Japanese Patent Publication No. 5-17183 discloses a 2-acrylamido-2-methylpropanoic acid-acryluriamide copolymer, which is a dust reducing agent for sprayed concrete. This invention also exerts an aggregating action on cement over time, leading to a decrease in fluidity of fresh concrete over time.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a high-flowability, high-fillability, high-separation-resistance property to fresh concrete without impairing the flowability when added in combination with a water reducing agent. It is an object of the present invention to provide an admixture for high-fluidity concrete that reduces or eliminates compaction during installation and to provide a concrete material having such properties. It is about.

[0007]

In view of the above situation,
As a result of intensive studies, it was found that the acrylamide-based water-soluble polymer, even at a concentration sufficient to suppress material separation and in combination with a water-reducing agent, did not impede the flowability, Not only imparts stable high fluidity, high filling property and high separation resistance, but also does not inhibit flow even when used in combination with a water reducing agent, and reduces or eliminates compaction during casting. I found something. That is, the present invention relates to the following. A unit derived from a compound represented by the following general formula (1): CH ₂ 1CR ¹ CONH ₂ (1) wherein R ¹ represents a hydrogen atom or a methyl group; Formula (2) CH ₂ ＣＲCR ² X ¹ R ³ SO ₂ X ² (2) (wherein R ² is a hydrogen atom or a methyl group, and R ³ is a carbon atom having 1 carbon atom.
4 to 4 linear or branched alkylene groups,
X ¹ represents CONH or COO, and X ² represents a hydrogen atom, an alkali metal, an ammonium salt or an organic ammonium salt. 1-60 percent by weight of units derived from a compound represented by), and the general formula ^{_{(3) CH 2 = CR 4}} X 3 ... (3) ( wherein R ⁴ is a hydrogen atom or a methyl group, X ³ is CN, C
OOR ⁷ , COR ⁸ , OCOR ⁹ and OR ¹⁰ are shown. Here, R ⁷ represents a hydrogen atom, an alkali metal, an ammonium salt, an organic ammonium salt or an alkyl group having 1 to 4 carbon atoms, and one hydrogen atom of the alkyl group is OH, N
(CH ₃ ) ₂ or N (C ₂ H ₅ ) ₂ . R ⁸ is an alkyl group having 1 to 4 carbon atoms, R ⁹ and R
¹⁰ is an alkyl group having 1 to 4 carbon atoms, N (CH ₃ ) ₂ or N (C ₂ H ₅ ) ₂ . 1) to 40% by weight of a unit derived from the compound represented by the formula (1) (the total sum of units derived from the compounds represented by the general formulas (1) to (3) is 100% by weight). Admixture for highly fluid concrete.

The unit derived from the compound represented by the general formula (1) is 40 to 89% by weight, the unit derived from the compound represented by the general formula (2) is 10 to 50% by weight, and the unit represented by the general formula (3) 1) to 30% by weight of the unit derived from the compound represented by the formula (1), wherein the total of the units derived from the compound represented by the general formulas (1) to (3) is 100% by weight. High fluidity concrete admixture. Or a cement supernatant of the polymer described.
When the viscosity of the 2% by weight aqueous solution is 2
The high fluidity concrete admixture of 0 cps or more and less than 1000 cps or described. A concrete material, wherein the admixture for high-fluidity concrete according to any one of the above is added to the cement paste. A concrete material comprising the admixture for a high-fluidity concrete and the water reducing agent according to any one of the above and cement paste.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, examples of the compound represented by the general formula (1) include acrylamide and methacrylamide. Examples of the compound represented by the general formula (2) include 2-acrylamido-2-methyl-propanesulfonic acid, 2-acrylamidoethanesulfonic acid,
-Methacrylamidoethanesulfonic acid, 3-methacrylamidopropanesulfonic acid, methyl acrylate acrylate, methyl methacrylate sulfonic acid, acrylic acid-2-
Ethylsulfonic acid, methacrylic acid-2-ethylsulfonic acid, acrylic acid-3-propylsulfonic acid, methacrylic acid-3-propylsulfonic acid, acrylic acid-2-methyl-3-propylsulfonic acid, methacrylic acid-2-methyl -3-propylsulfonic acid, acrylic acid-1, 1′-dimethyl-2-ethylsulfonic acid, meacrylic acid-1,
Examples thereof include 1'-dimethyl-2-ethylsulfonic acid and salts thereof. Compounds represented by the general formula (3), for example, methyl acrylate, ethyl acrylate, propyl acrylate, 2-hydroxyethyl acrylate, N, N-dimethylaminoethyl acrylate, acrylonitrile, methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, Examples include compounds such as vinyl acetate, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, methyl methacrylate, ethyl methacrylate, propyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and N, N-dimethylaminoethyl methacrylate. And preferably acrylonitrile.

The admixture for high-fluidity concrete comprising the acrylamide-based water-soluble polymer of the present invention comprises units derived from the compounds represented by the above-mentioned general formulas (1) to (3). The unit derived from the compound represented by the general formula (1) is at least 10% by weight, the unit derived from the compound represented by the general formula (2) is 1 to 60% by weight, and the unit derived from the compound represented by the general formula (3) is 1 unit
-40% by weight (the total sum of units derived from the compounds represented by the general formulas (1) to (3) is 100% by weight). The unit derived from the compound represented by the general formula (1) is preferably 4
0 to 89% by weight, more preferably 50 to 70% by weight, the unit derived from the compound represented by the general formula (2) is preferably 10 to 50% by weight, more preferably 20 to 40% by weight, the general formula (3 The unit derived from the compound represented by the formula (1) is preferably a copolymer comprising 1 to 30% by weight, more preferably 5 to 20% by weight.

When the content of the unit derived from the compound represented by the general formula (1) is less than 10% by weight, the content of the water-soluble polymer as the admixture for highly fluid concrete is less than 10% by weight. Depending on the molecular weight, the provision of viscosity is insufficient. When the content of the unit derived from the compound represented by the general formula (2) exceeds 60% by weight, it tends to be difficult to impart sufficient viscosity. When the content of the unit derived from the compound represented by the general formula (3) exceeds 40% by weight, the hydrophilicity of the polymer tends to decrease, and the viscosity and fluidity tend not to be imparted to fresh concrete.

The polymer used as the concrete admixture of the present invention has a 1.2% aqueous solution viscosity at 20 ° C. of 20 c.
The range is not less than ps and less than 1000 cps, and more preferably in the range of 40 cps to 680 cps. When the solution viscosity is lower than 20 cps, material separation occurs, which is not preferable. On the other hand, 1000
If it exceeds cps, the fluidity over time (slump flow value after 60 minutes) tends to decrease. In the present invention, the viscosity of a 1.2% aqueous solution of a polymer is defined as, after adding 3 liters of water to 30 g of Portland cement and stirring for 30 minutes,
1.2% by weight of polymer using the supernatant liquid left standing
Is a value obtained by measuring the viscosity of a liquid adjusted to a concentration of 1 at 60 rpm with a Brookfield-type rotational viscometer.

When high-fluidity concrete is used for on-site construction, it takes time to transport the concrete from a ready-mixed concrete manufacturing plant to the construction site. Therefore, it is required that the fluidity of the ready-mixed concrete does not significantly change even after a lapse of about 60 minutes immediately after the production. After filling the slump cone with ready-mixed concrete as an index,
It is required that the slump flow value after elapse of minutes is 55 cm or more, preferably 60 cm or more. From such a point of view, the concrete admixture of the present invention can provide the concrete composition with appropriate fluidity (the initial slump flow value is 55 cm or more), and at the same time, stability over time (after 60 minutes). Has a slump flow value of 55 cm or more), and has properties suitable as an admixture for highly fluid concrete.

As a method for producing the high fluidity concrete admixture of the present invention, methods such as aqueous solution polymerization, reversed phase suspension polymerization, precipitation polymerization and the like can be used, but are not particularly limited to these methods. Absent. As the polymerization initiator, a usual radical polymerization initiator can be used, and a peroxide such as t-butyl hydroperoxide, peroxide succinate, ammonium persulfate, potassium persulfate, or a peroxide or persulfate is used. A so-called redox initiator in which a reducing agent such as triethanolamine, sodium thiosulfate or sodium sulfite is present in the same system, furthermore, 2,2′-azobiz (2-amidinopropane) dihydrochloride, 2,2-azobis [2 -(2-imidazolin-2-yl) propane] dihydrochloride,
2,2′-azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (5-hydroxy-3,4,5,6 -Tetrahydropyrimidin-2-ylpropane] dihydrochloride, 2,2′-azobis [2
And azo initiators such as-(N-benzylamidinopropane) dihydrochloride.

As the modifier for the viscosity of the aqueous solution, n-butyl mercaptan, triethylamine, isopropyl alcohol, ammonium thioglycolate, sodium hypophosphite, etc., having a chain transfer effect can be used. The (co) polymer obtained by aqueous solution polymerization can be dried and pulverized into a powder. The (co) polymer obtained by the inverse suspension polymerization can be filtered and dried to obtain a powder. The resulting powder is added to the high fluidity concrete formulation as a powder. In addition, some of the aqueous solutions having low viscosity are hard to be made into powders, so that the aqueous solutions can be used as they are.

When using the admixture for high fluidity concrete of the present invention, it can be used in combination with another water reducing agent. The water reducing agent is not particularly limited as long as it is generally used as an admixture for concrete, and is preferably a naphthalene sulfonate formaldehyde condensate, a melamine sulfonate formaldehyde, a polycarboxylic acid or an ester or a salt thereof, or polystyrene. Sulfonates, cement dispersants having a phenol skeleton (formaldehyde co-condensates with other monomers capable of co-condensing with phenol sulfonic acid, etc.), cement dispersants containing aniline sulfonic acid as a main component (aniline sulfonic acid and And formaldehyde condensation products with other cocondensable monomers), and those referred to as conventional high-performance water reducing agents. The mixing ratio is 20 to the admixture for highly fluid concrete of the present invention.
To 800 times the weight is appropriate, preferably 100 to
400 times the weight.

The amount of the admixture for high fluidity concrete of the present invention is preferably in the range of 0.005 to 0.3% by weight in terms of solid content based on the hydraulic cement and the latent hydraulic composition. . The admixture for high fluidity concrete of the present invention can be used for concrete materials that are hydraulic compositions of cements such as civil engineering, construction, and secondary products. It is also possible to use a mortar material.
The concrete material of the present invention comprises an admixture for high-fluidity concrete, various cements constituting the concrete, an aggregate such as crushed stone, and an aggregate such as blast furnace slag, fly ash and silica fume. Can also be used. Examples of the additive include a retarder, an early strengthener, an accelerator, a foaming agent, a foaming agent, a water retention agent, a thickener, a waterproofing agent, an antifoaming agent, a water-soluble agent, and various surfactants. The concrete material using the admixture for high-fluidity concrete of the present invention has good initial fluidity and fluidity over time, has no material separation such as bleeding, and has excellent self-filling and leveling properties. It is a useful material as an admixture for fluidized concrete.

[0018]

【Example】

Example 1 A glass reactor was charged with 2-acrylamido-2-methyl-
30 g of propanesulfonic acid was dissolved in 890 g of water, and the pH was adjusted to 8 with sodium hydroxide. Add 60 g of acrylamide and 10 g of acrylonitrile,
After vigorous stirring and removal of dissolved oxygen by nitrogen aeration, 0.5 g of 2,2′-azobis (2-amidinopropane) dihydrochloride was added and reacted under nitrogen aeration. The obtained copolymer had a 1.2% aqueous solution viscosity of 89 cps.

Example 2 In a glass reactor, 2-acrylamido-2-methyl-
37.5 g of propanesulfonic acid was dissolved in 365 g of water, and the pH was adjusted to 8 with sodium hydroxide. After adding 75 g of acrylamide and 12.5 g of acrylonitrile and removing dissolved oxygen by aeration with nitrogen in a thermostat at 20 ° C., 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydro was added. 0.2 g of chloride was added and reacted under nitrogen aeration. After the completion of the reaction, the product was dried at 50 ° C. for 5 hours. After sufficient removal of water, the powder was reduced to 100 mesh or less by a small crusher. The obtained copolymer had a viscosity of 1.2% aqueous solution of 38.
It was 0 cps.

Example 3 In a glass reactor, 2-acrylamido-2-methyl-
30 g of propanesulfonic acid was dissolved in 890 g of water, and the pH was adjusted to 8 with sodium hydroxide. 60 g of acrylamide, 10 g of acrylonitrile and 0.1 g of ammonium thioglycolate were added and dissolved with 890 g of water. After vigorously stirring in a constant temperature bath at 50 ° C. and removing dissolved oxygen by nitrogen aeration, 0.5 g of 2,2′-azobis (2-amidinopropane) dihydrochloride
Was added thereto and reacted under a stream of nitrogen. The obtained copolymer had a 1.2% aqueous solution viscosity of 60 cps.

Example 4 In a glass reactor, 2-acrylamido-2-methyl-
30 g of propanesulfonic acid was dissolved in 890 g of water, and the pH was adjusted to 8 with sodium hydroxide. After 60 g of acrylamide, 10 g of acrylonitrile and 0.1 g of ammonium thioglycolate were added, and the mixture was vigorously stirred in a constant temperature bath at 50 ° C. to remove dissolved oxygen by nitrogen aeration, 0.3 g of ammonium persulfate and 0.1 g of sodium sulfite were added. In addition, the reaction was carried out under a stream of nitrogen. The obtained copolymer had a 1.2% aqueous solution viscosity of 70 cps.

Example 5 In a glass reactor, 2-acrylamido-2-methyl-
20 g of propanesulfonic acid was dissolved in 890 g of water, and the pH was adjusted to 8 with sodium hydroxide. 70 g of methacrylamide and 10 g of acrylonitrile are added, and 55
After vigorously stirring in a constant temperature bath at 0 ° C. and removing dissolved oxygen by nitrogen aeration, 0.5 g of ammonium persulfate and 1.5 g of sodium sulfite were added and reacted under nitrogen aeration. The resulting copolymer had a 1.2% aqueous solution viscosity of 52%.
cps.

Example 6 In a glass reactor, 30 g of methacrylic acid-2-ethylsulfonic acid was dissolved in 365 g of water, and the pH was adjusted to 8 with sodium hydroxide. 87.5 g of methacrylamide
And 12.5 g of acrylonitrile, and after removing dissolved oxygen by nitrogen aeration in a 20 ° C. constant temperature bath, 2,2′-azobis [2- (2-imidazoline-2) was added.
-Yl) propane] dihydrochloride (0.2 g) and reacted under a stream of nitrogen. After completion of the reaction, the product is
Dry at 50 ° C. for 5 hours. After sufficient removal of water, the powder was reduced to 100 mesh or less by a small crusher. The resulting copolymer had a 1.2% aqueous solution viscosity of 380 cps.

Example 7 In a glass reactor, 2-acrylamido-2-methyl-
30 g of propanesulfonic acid was dissolved in 890 g of water, and the pH was adjusted to 8 with sodium hydroxide. 55 g of acrylamide and 15 g of methyl vinyl ketone are added, and 55
After stirring vigorously in a constant temperature bath at ℃ and removing dissolved oxygen by nitrogen aeration, 0.4 g of potassium persulfate and 1.2 g of sodium sulfite were added and reacted under nitrogen aeration. The resulting copolymer had a 1.2% aqueous solution viscosity of 67 cp.
s.

Example 8 In a glass reactor, 2-acrylamido-2-methyl-
37.5 g of propanesulfonic acid was dissolved in 365 g of water, and the pH was adjusted to 8 with sodium hydroxide. After adding 68.75 g of acrylamide and 18.75 g of 2-hydroxyethyl methacrylate, and removing dissolved oxygen by nitrogen aeration in a thermostat at 20 ° C.,
2'-azobis [2- (2-imidazolin-2-yl)
Propane] dihydrochloride (0.2 g) was added, and the mixture was reacted under nitrogen aeration. At the end of the reaction, the product is
Dried for hours. After sufficient removal of water, the powder was reduced to 100 mesh or less by a small crusher. The resulting copolymer had a 1.2% aqueous solution viscosity of 380 cps.

Comparative Example 1 In a glass reactor, 2-acrylamido-2-methyl-
30 g of propanesulfonic acid was dissolved in 890 g of water, and the pH was adjusted to 8 with sodium hydroxide. Add 60 g of acrylamide and 10 g of acrylonitrile,
After vigorous stirring and removal of dissolved oxygen by nitrogen aeration, 3.0 g of 2,2'-azobis (2-amidinopropane) dihydrochloride was added, and the mixture was reacted under nitrogen aeration. The obtained copolymer had a 1.2% aqueous solution viscosity of 13 cps.

Comparative Example 2 In a glass reactor, 2-acrylamido-2-methyl-
37.5 g of propanesulfonic acid was dissolved in 365 g of water, and the pH was adjusted to 8 with sodium hydroxide. After adding 75 g of acrylamide and 12.5 g of acrylonitrile and removing dissolved oxygen by aeration with nitrogen in a thermostat at 20 ° C., 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydro was added. 0.05 g of chloride was added and reacted under nitrogen aeration. After the completion of the reaction, the product was dried at 50 ° C. for 5 hours. After sufficient removal of water, the powder was reduced to 100 mesh or less by a small crusher. The resulting copolymer had a 1.2% aqueous solution viscosity of 520.
cps.

Comparative Example 3 In a glass reactor, 2-acrylamido-2-methyl-
58 g of propanesulfonic acid was dissolved in 890 g of water, and the pH was adjusted to 8 with sodium hydroxide. 8 g of acrylamide and 34 g of acrylonitrile were added, and the mixture was vigorously stirred in a 55 ° C. constant temperature bath, and dissolved oxygen was removed by aeration with nitrogen. Then, 0.5 g of 2,2′-azobis (2-amidinopropane) dihydrochloride was added. The reaction was carried out under a stream of nitrogen. The obtained copolymer had a 1.2% aqueous solution viscosity of 77 cps.

Comparative Example 4 In a glass reactor, 2-acrylamido-2-methyl-
70 g of propanesulfonic acid was dissolved in 890 g of water, and the pH was adjusted to 8 with sodium hydroxide. Add 20 g of acrylamide and 10 g of acrylonitrile,
After vigorous stirring and removal of dissolved oxygen by nitrogen aeration, 0.5 g of 2,2′-azobis (2-amidinopropane) dihydrochloride was added and reacted under nitrogen aeration. The obtained copolymer had a 1.2% aqueous solution viscosity of 42 cps.

Comparative Example 5 In a glass reactor, 2-acrylamido-2-methyl- was added.
25 g of propanesulfonic acid was dissolved in 890 g of water, and the pH was adjusted to 8 with sodium hydroxide. Add 30 g of acrylamide and 45 g of acrylonitrile,
After vigorous stirring and removal of dissolved oxygen by nitrogen aeration, 0.5 g of 2,2′-azobis (2-amidinopropane) dihydrochloride was added and reacted under nitrogen aeration. The obtained copolymer had a 1.2% aqueous solution viscosity of 71 cps.

In order to examine the effects of the copolymers obtained in Examples 1 to 8, evaluation was made by a test using concrete. Table 1 shows the composition of the concrete. Table 2 shows the evaluation results.
Shown in The amount of the water reducing agent was adjusted so that the slump flow became 55 to 65 cm.

[0032]

[Table 1]

Cement (C): Ordinary Portland cement (specific gravity 3.16) Fine aggregate (S): Kinokawa river sand (specific gravity 2.60) Coarse aggregate (G): Takarazuka crushed stone (specific gravity 2.63) Water ( W): Tap water

[0034]

[Table 2]

* 1 Slump flow value is measured according to JIS
A 1101. * 2 Judged with the naked eye. ○: No separation of aggregate and cement paste ×: Separation of aggregate and cement paste * 3 Put the produced concrete into a cylindrical form with a diameter of 10 cm, pack it without using a vibrator, leave it for 3 days, then remove it from the mold The state of filling of the concrete surface was visually observed. …: Almost no voids of 0 to 5 mm or more are observed. ×: Many voids of 5 mm or more are generated. * 4 Naphthalenesulfonic acid condensate (Mighty 2000
WHX manufactured by Kao Corporation * 5 Polycarboxylic acid (Mighty 2000WHZ manufactured by Kao Corporation) * 6 Melamine sulfonic acid condensate (Molmaster F-3)
00 Showa Denko Co., Ltd. * 7 Lignin sulfonic acid compound Polyol condensate (Pozzolith No. 70, Pozzoli Co., Ltd.) * 8 Aromatic aminosulfonic acid (Palic SAO
Fujisawa Pharmaceutical Co., Ltd.)

[0036]

The fresh concrete to which the admixture for high-fluidity concrete of the present invention is added has high fluidity, high filling property and high separation resistance, and reduces compaction during casting.
Alternatively, an excellent effect, such as making it unnecessary, is provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 24/28 C04B 24/28 C08F 216/02 C08F 216/02 216/36 216/36 218/02 218/02 220/38 220 / 38 220/44 220/44 220/56 220/56 // C04B 103: 32

Claims (5)

[Claims] 1. A unit derived from a compound represented by the general formula (1): CH ₂ ＣＲCR ¹ CONH ₂ (1) wherein R ¹ represents a hydrogen atom or a methyl group. % By weight, general formula (2) CH ₂ = CR ² X ¹ R ³ SO ₂ X ² (2) (wherein R ² is a hydrogen atom or a methyl group, and R ³ is a carbon atom of 1
4 to 4 linear or branched alkylene groups,
X ¹ represents CONH or COO, and X ² represents a hydrogen atom, an alkali metal, an ammonium salt or an organic ammonium salt. 1-60 percent by weight of units derived from a compound represented by), and the general formula ^{_{(3) CH 2 = CR 4}} X 3 ... (3) ( wherein R ⁴ is a hydrogen atom or a methyl group, X ³ is CN, C
OOR ⁷ , COR ⁸ , OCOR ⁹ and OR ¹⁰ are shown. Here, R ⁷ represents a hydrogen atom, an alkali metal, an ammonium salt, an organic ammonium salt or an alkyl group having 1 to 4 carbon atoms, and one hydrogen atom of the alkyl group is OH, N
(CH ₃ ) ₂ or N (C ₂ H ₅ ) ₂ . R ⁸ is an alkyl group having 1 to 4 carbon atoms, R ⁹ and R
¹⁰ is an alkyl group having 1 to 4 carbon atoms, N (CH ₃ ) ₂ or N (C ₂ H ₅ ) ₂ . 1) to 40% by weight of a unit derived from the compound represented by the formula (1) (the total sum of units derived from the compounds represented by the general formulas (1) to (3) is 100% by weight). Admixture for highly fluid concrete. 2. A unit derived from the compound represented by the general formula (1) is 40 to 89% by weight, a unit derived from the compound represented by the general formula (2) is 10 to 50% by weight, and the unit represented by the general formula (3) 2. The admixture according to claim 1, wherein the unit derived from the compound represented by the formula (1) comprises 1 to 30 weight parts. 3. The method according to claim 1, wherein the polymer supernatant liquid of the polymer according to claim 1 or 2 has a viscosity of 1.2% by weight in an aqueous solution of not less than 20 cps and less than 1000 cps in a B-type rotational viscometer. Admixture for fluidized concrete. 4. A concrete material wherein the admixture for high-fluidity concrete according to claim 1 is added to a cement paste. 5. A concrete material comprising the cement paste and the admixture for high-fluidity concrete according to claim 1 together with a water reducing agent.